We will offer three different pre-order packages for all early birds out there who would like to support our development, those packages will include access to our alpha, beta, early access and some fancy bonus contents. Make sure to follow at least one of our social media channels (Twitter , Facebook , Instagram) or our news forum, as the exact date of the pre-order and alpha start (plus all kind of progress videos/screenshots) will be announced there.

Dear Community,
we thought it's a good idea to release a little sum-up of what we've worked on the last few weeks, the list also includes 'behind the scenes' stuff which we haven't covered on our site yet, hopefully this gives you guys a good update on our progress.
Engine: Our first prototype has been updated to Unity's 2017.4 LTS (Long Term Stability), which we plan to use for our first release. This version is guaranteed to receive bugfixes without major changes which could break backward compatibility. This version has also been the most stable one for us so far.
Terrain: Progress is looking good, we also had some major workflow improvements.
Networking: All player movements are now double-checked by the server instance (authoritative movement) to address teleport- and no-clip hacks.
Networking: Interpolation added.
Networking: Dead reckoning added.
Networking: Lag compensation is still being worked on.
Combat: Damage drop off for range weapons is now properly calculated.
Character: Improved character controller handling on slopes.
Character: Weapon handling has been optimized when activating/deactivating them.
Animations: Workflow improved for animation retargeting (especially for motion captured ones).
Weapons: 1866 Yellowboy Rifle added (https://twitter.com/DeadMansCountry/status/979384778855247873).
Weapons: 1861 Navy Conversion Revolver added (https://twitter.com/DeadMansCountry/status/979747245422776320).
Weapons: 1860 Double Barrel Shotgun added (https://twitter.com/DeadMansCountry/status/980102521426497536).
Weapons: 1874 Sharps Rifle added (https://twitter.com/DeadMansCountry/status/981503473819713538).
Weapons: Tomahawk added, melee combat still needs some love though (https://twitter.com/DeadMansCountry/status/983724748076208128).
Weapons: 1858 New Model Army Revolver added (https://twitter.com/DeadMansCountry/status/988703525369733120).
Weapons: Sticky bomb added (https://twitter.com/DeadMansCountry/status/992008560912601088).
Shader: Various post-processing stack improvements.
Shader: New ambient occlusion modes added (MSVO and SAO).
Shader: Our character skin shader is almost finished (https://twitter.com/DeadMansCountry/status/980909856361275392).
Shader: We've implemented a motion blur shader which relies on the moving object instead of the player's camera (https://twitter.com/DeadMansCountry/status/984723884367892480 ).
Shader: Volumetric lighting improved.
UI: There is some good progress on our UI, nothing to show yet, but we posted an early mockup from some months ago (https://twitter.com/DeadMansCountry/status/981153951218270209).
Environment: We finished our grass shader with physically based shading support (https://twitter.com/DeadMansCountry/status/981917793812697090).
Environment: Our grass shader also supports touch bending now (https://twitter.com/DeadMansCountry/status/983345950042345473).
Environment: Mesh blending has been added (https://twitter.com/DeadMansCountry/status/982299162569035777).
Environment: New canyon walls (https://twitter.com/DeadMansCountry/status/993926569491140609).
Props: We continuously working on adding new props (https://twitter.com/DeadMansCountry/status/982702739250733056, https://twitter.com/DeadMansCountry/status/984137263062937611, https://twitter.com/DeadMansCountry/status/990934430691790848).
Placements: A new feature has been added which removes all kind of foliage for dynamic placements. (https://twitter.com/DeadMansCountry/status/985960044469587970).
Equipment: Tribal mask added (head item, https://twitter.com/DeadMansCountry/status/987298912259248128).
Particles: We improved our particles in regards to lighting (https://twitter.com/DeadMansCountry/status/989497266582052865).
Particles: Worked on our revolver muzzle flash (https://twitter.com/DeadMansCountry/status/995994191510605825).
Farming: We made great progress on our crop/tree grow system, which is also fully server-synced and runs with almost no performance cost (https://twitter.com/DeadMansCountry/status/997478138169970688).
Environment: Our ore spawning algorithm got some love (https://twitter.com/DeadMansCountry/status/999247022539583488).
API: A device token has been added, which will later be used as a parameter to identify account hacks.
Forum: News & Announcements module added (you are here!).
Please note that the list is in no particular order and doesn't include bugfixes, the later will be listed with the start of the alpha on a separate release-/changelog page.

I agree it'll not be an easy job, but the alternative would be a very limited building area and/or pre-defined building slots, both wouldn't fit in our concept. Some of the bugs/exploits you mentioned can be fixed by adding a minimum distance radius to each object (except walls), which is something we're currently working on. As for walls, we could allow the AI to climb/jump over/destroy them depending on the size/strength of the controlled entity.

The dollar is the main currency in Dead Man's Country, but there are some NPC's which require special items in order to trade with them. Players will probably prefer water over hard cash because of its limitation.
Yes, players will be able to trade through a traditional trade-window.